Individual bobbin spindle stop motion for a twister

ABSTRACT

The apparatus stops take up and feed functions of a yarn twister while means detects a broken or exhausted yarn feed and activates a control system, which through a linkage mechanism, simultaneously disengages the bobbin from the drive twirl and stops same with a brake. The system may be reset after activation but will again activate if the missing yarn has not been replaced.

United States-Patent 1191 Pugh Aug. 13, 1974 i 1 INDIVIDUAL BOBBIN SPINDLE STOP 3,166,883 1/1965 Meadows 57/88 MOTION FOR A TWISTER 3,388,544 6/1968 Hamel 57/8I 3,498,039' 3/1970 Kentet al. 57/8l X Inventor: Charles gh, url1ngton,N.C. 3,523,415 8/1970 Suzuki 57/81 [73] Assignee: Burlington Industries, Inc., v

Greensboro, N,C Primary Examiner-Donald E. Watkms D b & Filed: Jan. 1 9 Agent, or Fzrm Cushman, ar y 21 Appl. No.1 324,215

[57] ABSTRACT [52] Cl 57/81, 57/83, 57/88 The apparatus Stops take up and feed functions of [51] IIII. Cl D01]! 13/16 yam twister while means detects a broken or [58] Fleld of Search 57/78, 80, 81, 82, 83, hausted yam feed and activates a control system 57/84 88 which lsl a l n g m q lapi mz..simu anw y, disengages the bobbin from the drive twirl and stops [56] Referemis C'ted same with a brake. The system may be reset after acti- U D S TE ATENTS vation but will again activate if the missing yarn has 2,565,500 8/1951 lngham 57/81 x not been replaced- 2,704,430 3/1955 Harris 57/81 2,984,964 5/1961 Bates 57/81 x 16 Clam, 5 Drawmg Figures /7 e fl 20 ii I I T T |1| 29 1 INDIVIDUAL BOBBIN SPINDLE STOP MOTION FOR A TWISTER BACKGROUND OF THE INVENTION 5 l. Fieldof Use The invention relates to a device for stopping take up of a spindle mechanism fixed with a yarn twister. I

2. Description of Prior Art Two or more ends of yarn may be twisted together on which is engaged with the spindle twirl so that it will rotate with the spindle. If any one of the fyarns fed to the spindle to' form the twisted yarn breaks, then the twisted yarn will become second quality, which results in waste and will drastically reduce its sale value.

It is desirable to have a means of immediately detecting the absence of a yarn feeding a spindle then stopping further collection of yarn on the bobbin. This has been accomplished in the prior art by two principal methods as described below.

In both methods-the yarn breakage is detected by a mechanical or photo-electric type switch which may be used to activate a control system for stopping thetake up. The switch in one method activates a cutter which will sever all remaining yarns fed to the spindle should one yarn break. A major disadvantage of this method is the fact that the cut ends of yarn continue to whirl around with the bobbin, and after a period of time, the ends tend to become entangled .with adjacent bobbins causing further problems.

In a second method, the yarn detecting switches activate a mechanism which stops the yarn fed to a spindle and simultaneously stops the spindle rotation which, of course, stops the bobbin from further winding yarn around it. The yarn feed is stopped by separating the feed rolls from the yarn. The spindle rotation may be stopped by means of a clutch mechanism which indirectly drives the spindle from the belt'drive. This system is good for machines already equipped with the clutch mechanism on each spindle, but in most cases it is impractical to install clutch mechanisms on machines built with a direct belt drive to each spindle twirl.

In variations on the above methods, delicate balancing devices have been used which hold a feed roll in place and, while these systems are workable, vibrations can easily activate them. Other methods use linkages to separate the spindle from a drive mechanism but these systems again involve complex and costly elements which are susceptible to premature activation.

It is an object of the present invention to provide a mechanism which obviates one or more of the disadvantages and limitations of the described prior arrangements.

It is another object of the present invention .toprovide an economical and simple mechanism for stopping yarn feed in a twisting machine when any of the individual threads of yarn making up the plied yarn breaks.

It is yet another object of the present invention to provide a control system for accomplishing the-above result.

SUMMARY OF THE INVENTION According to the present invention, apparatus for stopping take up and feed functions in a yarn twister is provided wherein a plurality of drivetwirls and bobbins driven thereby, each take up a plurality of yarn strands from a supply as each bobbin rotates. Drive means including a drive and pressure roller set for each selected number of yarn strands draws the yarn at a selected rate for its associated bobbin, while a yarn ring following the bobbin guides the number of yarn strands for twisting as the bobbin rotates. The system comprises means for each yarn strand for detecting termination of yarn supply of any one ofsaid yarn strands and producing an output indication thereof while means operatively coupled with each bobbin responds to the output for disengaging the bobbin out of driving relationship withthe twirl.

For a better understanding of the present invention, together with other and further objects thereof, reference is directed to the following description, taken in connection with the accompanying drawings, while its scope will be pointed out in the appended claims.

DESCRIPTION OF THE DRAWINGS FIG. 1 is an isometric view of the twister incorporating the apparatus of the present invention;

FIG. 2 is a side elevation of the apparatus of the present invention in a reset or cocked condition;

FIG. 3 is a view of FIG. 2 in the released position;

FIG. 4 is an isometric view of a detail of the present invention;

FIG. 5,.is a schematic diagram of the control circuit.

used with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT This invention relates particularly to apparatus for converting twisters that have direct drive spindles into an individual spindle stop motion machine. The method utilized is firstly, to detect yarn breakage through either a mechanical or electronic means, and

secondly, to activate a spring loaded mechanism from the yarn detector that will disengage the bobbin from the spindle twirl. Further means is provided for disengaging the yarn feed rolls simultaneously with the disengagement of the spindle plus bobbin. The spindle twirl will-continue to rotate through the belt, butthe bobbin will stop, thereby stopping the yarn collection.

This invention is intended to be used on twisters or spinning frames that utilize a twirl, mentioned above, or equivalent, to engage the bobbin to the spindle as explained further below.

Referring to FIG. 1 for an example of one possible configuration to accomplish the above bobbin stop, there is shown the well-known method of twisting multiple yarns and collecting the resulting yarn on a bobbin. Yarn spools 9 provide a supply of yarns 10 which are fed through guides 11, then between respective upper and lower feed rollers 12 and 13. The strands 10 are grouped or plied intoa yarn 14 and fed through a loop 21a in a free spinning follower 21b riding in a reciprocating frame 23. The frame 23 reciprocates between the end points 15A and 15B of bobbin 15. The amount of twist in the yarn 14 is governed by the lag between the RPM of the spinning bobbinlS and the RPM of the follower 21b, control of which is wellknown in the art.

Bobbin 15 is fitted over a spindle shaft 17 by means of a hole 18 through the center of the bobbin 15 and sets down upon and engages with spindle twirl 16by a mating slot cut 19 in the bobbin engaging with bar 20. The twisted yarn 14 is collected into a package on bobbin 15 under control of the reciprocating traveler 23 as previously mentioned.

The method of halting yarn collection on bobbin 15 should any one of yarns break, consists of raising weighted free rolling upper feed rollers 12 up off driven feed rollers 13 and simultaneously pushing bobbin up off spindle twirl 16 and applying a brake pad 22 to it, such that it stops rotation. The bobbin at rest is supported by spindle shaft 17 which continues to rotate. Details of how this is accomplished follows:

Yarn detection switches 23 monitor each end of yarns 10 such that if any end breaks or runs out, a signal is sent to any electronic circuit 24 through wires 25. This signal causes momentary actuation of a solenoid 26 which activates latch 28 immediately after activation of circuit 24. Electronic circuit 24, shown in detail in FIG. 5, is discussed below. The electronic circuit 24 operates solenoid 26 and presses latch 28 laterally, as viewed in FIG. 3 which allows a spring 29 to contract and pull a lever 30 downward.

This action, shown in detail in FIGS. 2 and 3, which are side views of the apparatus of the invention of FIG. 1, except that FIG. 1 is shown in isometric form. Further FIG. 2 is shown reset or cocked while FIG. 3 in the tripped or stop bobbin position.

Referring to FIG. 2, note that latch 28 is normally vertical in the reset position. Latch 28 has a ledge or retaining portion 31 which holds lever 30 in the cooked position. However, when solenoid 26 is activated, plunger 32'disposed therein moves laterally (in FIG. 3 to the right) for pushing latch 28 away to the extent that its retaining ledge 31 releases arm or lever 30. Latch member 28 is a member sufficiently flexible to bend under theinfluence of plunger 32. In FIG. 4 it can be seen that latch 28 is secured to frame member 57 by appropriate fasteners 58.

When lever 30 is released, a spring 29 contracts pulling lever 30 downward at one end and raising the other end about pivot 33 (See FIG. 4). The action of lever 30 pulls linkage 34 which in turn pulls bracket35 down, jacking rollers 12 up off rollers 13 which disengages the feed rollers, and further brake pad 22 coupled to lever 30 pushes the bobbin 15 up off the spindle twirl 16 and further brake pad 22 engaging with the bottom of the bobbin 15, causes it to stop. The spindle shaft 17 can turn freely in the hole 18 in bobbin 15, thereby permitting the spindle twirl17 to continue rotating with bobbin 15 stopped. Thus, in this condition the twisted yarn 14 is stopped since both the feed rollers 12 and 13 are separated from each other and the bobbin 15 is stopped. Once the circuit 24 has been tripped, solenoid plunger 32 is immediately reset by circuit 24.

FIG. 5 shows details of the electronic circuit 24, the function of which is to cause solenoid 26 to trip the latch 28 momentarily. If a strand of yarn breaks or runs out, a corresponding one of the sensitive yarn switches 23, represented by dotted box SW,, is closed. If the missing yarn has not been replaced and lever 30 has been placed in the reset position, circuit 24 will thereupon go through a time delay and again activate 26 momentarily causing the apparatus to assume the tripped position as in FIG. 3.

An AC voltage is applied continuously across terminals 40. A diode 41 and input capacitor 42 provide a half wave filtered DC potential to the yarn detector switch SW, through a resistor 43. SW, could be a mechanical tension controlled switch as shown. or a semiconductor such as a transistor or photodetector. For example, switches 23 of switch unit SW, can be a flexible member or arm 23A coupled to a contactor which is open under one condition, i.e., when under tension from an unbroken thread 10 held taut between spool 9 and guide 11, and is closed when a thread breaks releasing arm 23A. Further, there are semiconductor selectors having a photocell disposed in one side of a body and light source in the other. As' the thread passes between the cell and source the light impinging in the detector fluctuates generating a signal which may be utilized to indicate an unbroken strand. When and if a strand breaks the response of the photo detector to the light will be constant since the thread is no longer moving, between the cell source due to a break therein.

Returning to the description of FIG. 5 with SW, open, the DC potential provides sufficient base drive to a transistor 44 to cause it to be saturated. This places a low-or ground on the collector of transistor 45 and also the gate G input of a triac 46 holding same of or non-conductive. Solenoid 26 is in series with triac 46 and, therefore, it also is off or inactivated.

Assume transistor 44 is on", and the apparatus is in the reset position as in FIG. 1. Consider the action when any switch 23 of SW, closes. The base of transistor 44 is grounded which turns 44 off allowing resistor 47 to apply AC voltage to the collector of transistor 45 and the gate G of triac 46. The triac is thus activated, which causes current to flow through solenoid 26, thereby activating latch 28 via plunger 32. When solenoid is activated, latch 28 will release lever 30 causing the yarn 32 feed and take up to stop as explained above.

FIG. 4 shows a detail of the system as previously described whereinmicro switch 48 is mounted on frame member 55 and trip lever 56 of switch 48 engages with lever 30 when in the cocked position. Further, switch 48 closes its contacts when lever 30 releases trip lever 56. Closure of switch 48 (see FIG. 5) establishes a path of current through diode 41 to the base of transistor 45 1 through resistor 50 for holding same on" and thereby grounding the gate G of triac 46 for resetting solenoid 26 as previously mentioned.

Therefore, a momentary action of solenoid 24 occurs each time SW, goes from an open positionto a closed position and lever 30 is released thereby closing switch 48 and deactivating solenoid 26.

Assume that any one of switches 23 in switch unit SW, was closed, causing the circuit to momentarily activate solenoid 26 as above, then assume all switches in switch unit SW, become open, implying that a missing yarn has been replaced. If SW, is opened and lever 30 is put in the reset position as in FIG. 1, then the circuit will cause no further action and the system will operate continuously as in FIG. 1.

Now consider that at least one of the switches 23 in switch unit SW, is closed causing lever 30 to trip as in FIG. 2 and then lever 30 is put into the reset position as in FIG. 1. However, SW remains closed, implying the missing yarn has not been replaced and the bobbin is restarted. The result will be explained below.

Referring to FIG. 5 with switch 48 in the closed position, i.e., lever 30 down, capacitor 52 is charged to a bias level which saturates transistor 45. After switch 48 is opened, i.e., lever 30 reset, the charge in capacitor 52 does not immediately drain off, but the amount of time this bias is applied to transistor 45 is determined by the RC time constant of capacitor 52 and base resistor 50.

This means that transistor 45 will be saturated thereby holding triac 46 off for a selected period immediately after switch 48 is opened, regardless of the condition of switch SW If SW remains closed, implying a missing strand 10, the charge on capacitor 52 will eventually drain off through resistor 50. However, while transistor 45 is on, i. e;, saturated due to the condition of capacitor 52, the gate G of triac 46 will be held at ground or low and the triac 46 will thereby be a non-conductive. Once the transistor 45 becomes nonconductive, i.e., after the capacitor 52 has discharged transistor 45 relinquishes control to transistor 44. Consequently, with SW closed, transistor 44 is off, allowing resistor 47 to provide bias to the gate G of triac 46, which again momentarily operates solenoid 26. Each time lever 30 is reset and SW, remains closed, there will be-time delaydetermined by the RC time constant after which solenoid 26 will again activate momentarily.

The restart cycle previously mentioned will now be explained in detail relative to FIG. 1.

In order to return the mechanism to the reset or cocked position after the bobbin has been raised, force is applied, generally inwardly, on lever 58 as shown;

Lever 58 has brake pads (not shown) located on it just under the bottom of twirl 16. As force is applied to lever 58 it causes the brake pads to friction stop twirl 16 causing drive belt 56 to slip. Note that lever 58 has lever 59 attached to it such that if a force is exerted on lever 58, it moves inward and lever 59 moves upward as shown by the arrow. The inward force also causes lever 59 to move upward to push pick up arm 60 which is attached to lever 30. As lever 30 is pushed up the spring 29 is stretched and the bobbin is lowered down on the twirl (now stopped by the action of the brake pads against the under side of twirl 19) and the rollers 12 are lowered. As the force on lever 58 is continued lever 59 lifts lever 30 up past notch 31 of lever 28 and lever 28 springs inward toward lever 30 (left) such that when force is removed from lever 58, lever 30 will remain engaged with the notch in lever 28 holding the mechanism in the cocked position. Further, as the pressure on lever 58 is released the brake pad is removed from twirl l6 and the belt once again turns the twirl which turns the bobbin 15. It is necessary to momentarily stop the twirl 16 so that the bobbin 15 may be replaced. It is generally understood with this type of machine that they have arm operating speeds in the order of 5,000 PRM and would not operate properly if the twirls were not momentarily stopped for replacing the bobbins 15.

From the foregoing it can be seen that an efficient 7 problems inherent in such complex modification have and easily manufactured modification of an existing twister has been accomplished without the need for drastic remodeling of the basic apparatus. Further, the

been obviated.

While there has been described what at present is considered to be the preferred embodiment of the present invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention and it is intended in the following claims to cover such modifications as fall within the true' spirit and scope of the invention.

What is claimed is:

1. Apparatus for stopping take up and feed functions in a yarn twister;

wherein each of a plurality of spindle twirls and bobbins having a drive therefor, take up a selected number of yarn strands from a yarn supply as each of said bobbins rotate, drive means, including a drive and pressure roller set for each selected number of yarn strands, for drawing said yarn strands at a selected rate of the associated bobbin, and a reciprocating yarn ring following the bobbin, guiding the number of yarn strands for twisting and take up as the bobbin rotates, comprising: means for each yarn strand for detecting the termination of the yarn supply of any one of said yarn strands and producing an indication thereof, and means operatively associated with each bobbin, re-

sponsive to the indication means, for disengaging said bobbin out of driving relationship with said spindle twirl and for stopping rotation of said bobbin. 2. Apparatus as described in claim 1 including: means coupled to said indication responsive means for separating said pressure roller from said drive roller for stopping feed of said yarn strands, whereby the simultaneous stopping of take up motion of said individual bobbin and feed action of said drive means is accomplished. 3. The apparatus as described in claim 1 wherein said means responsive to the indication means comprises: control means including a latch member having a recess for engaging and holding said means in one condition and for releasing said means in response to said detector means output.

4. The apparatus as described in claim 3 wherein said control means includes a solenoid and actuating circuit therefor for momentarily actuating said latch means thereby releasing same.

5. The apparatus as described in claim 3 wherein said control means comprises:

electronic circuit means responsive to said detector means output for providing a trigger signal in response thereto, including switching means providing a path for electrical energy for said trigger signal.

6. The apparatus as described in claim 5 wherein said electronic circuit means includes:

a triac energized by said switching means for providing said trigger signal and said switching means includes at least one transistor switch.

7. The apparatus of claim 3 wherein said means responsive to the indication means includes:

a latch, a solenoid engaging with an end of said latch, which maintains said means in one operative state,

said solenoid momentarily activating said latch under the influence of a detector output for releasing said means to a second operative state.

8. The apparatus of claim 3 wherein said means responsive to the indication means includes:

a lever associated with each of said bobbins and pressure roller sets operatively engaged with said latch for releasing same such that both said bobbin and pressure rollers are respectively moved out of operative relationship with said twirl and drive rollers when said latch is actuated and the lever associated with the bobbin includes a brake pad engaging with the bobbin for stopping same when activated.

9. The apparatus of claim 8 wherein said means responsive to the indication means further includes:

a spring means operatively coupled to said lever for accomplishing said motion, after said latch releases said lever and said means further includes a second lever engaging with said first mentioned lever for resetting same from said released condition, said latch and lever thereby holding said bobbin and pressure rollers into operative relation with said respective twirl and drive rollers 10. The apparatus of claim 9 wherein said detector means includes time delay means for retaining said means, for a selected interval, after said second lever is activated, said interval governed by a resistor, capacitor delay circuit and responsive to said detector means for providing a trigger signal if any one of said strands is terminated.

11. The apparatus of claim 3 wherein said detector means further includes switch means operatively coupled with said means for producing signals indicative of reset and release conditions, for producing an enabling signal for said control means to release said latch after said lever is reset from its released position unless a terminated strand associated therewith is replaced.

12. The apparatus as described in claim 1 wherein said detector means comprises:

photodetector means responsive to each strand of yarn and each coupled to said control means for producing a signal indicative of yarn termination.

13. The apparatus as described'in claim 1, wherein said detector means comprises:

means for each strand responsively coupled thereto having at least two states, a first state for providing indication of a continuous strand and a second state indicative of the termination of said strand.

14. The apparatus as described in claim 7, further including:

reset means for momentarily stopping said twirl from rotation while said bobbin is replaced thereon and said means engages with said control means for resetting said detector means.

15. The apparatus as described in claim 7 wherein said latch includes a bar fixed at one end and engaging with the solenoid at the other end thereof having a ledge member for holding said lever in reset position and releasing same when urged laterally by the activation of said plunger, said latch being relatively flexible and tending to flex back to the unreleased condition when the lever is reset.

16. The apparatus as described in claim 1 wherein said means responsive to the indication means for disengaging the bobbin out of driving relation with the bobbin drive includes: a lever, for disengaging said bobbin out of driving relation with the spindle twirl and stopping rotation thereof. 

1. Apparatus for stopping take up and feed functions in a yarn twister; wherein each of a plurality of spindle twirls and bobbins having a drive therefor, take up a selected number of yarn strands from a yarn supply as each of said bobbins rotate, drive means, including a drive and pressure roller set for each selected number of yarn strands, for drawing said yarn strands at a selected rate of the associated bobbin, and a reciprocating yarn ring following the bobbin, guiding the number of yarn strands for twisting and take up as the bobbin rotates, comprising: means for each yarn strand for detecting the termination of the yarn supply of any one of said yarn strands and producing an indication thereof, and means operatively associated with each bobbin, responsive to the indication means, for disengaging said bobbin out of driving relationship with said spindle twirl and for stopping rotation of said bobbin.
 2. Apparatus as described in claim 1 including: means coupled to said indication responsive means for separating said pressure roller from said drive roller for stopping feed of said yarn strands, whereby the simultaneous stopping of take up motion of said individual bobbin and feed action of said drive means is accomplished.
 3. The apparatus as described in claim 1 wherein said means responsive to the indication means comprises: control means including a latch membeR having a recess for engaging and holding said means in one condition and for releasing said means in response to said detector means output.
 4. The apparatus as described in claim 3 wherein said control means includes a solenoid and actuating circuit therefor for momentarily actuating said latch means thereby releasing same.
 5. The apparatus as described in claim 3 wherein said control means comprises: electronic circuit means responsive to said detector means output for providing a trigger signal in response thereto, including switching means providing a path for electrical energy for said trigger signal.
 6. The apparatus as described in claim 5 wherein said electronic circuit means includes: a triac energized by said switching means for providing said trigger signal and said switching means includes at least one transistor switch.
 7. The apparatus of claim 3 wherein said means responsive to the indication means includes: a latch, a solenoid engaging with an end of said latch, which maintains said means in one operative state, said solenoid momentarily activating said latch under the influence of a detector output for releasing said means to a second operative state.
 8. The apparatus of claim 3 wherein said means responsive to the indication means includes: a lever associated with each of said bobbins and pressure roller sets operatively engaged with said latch for releasing same such that both said bobbin and pressure rollers are respectively moved out of operative relationship with said twirl and drive rollers when said latch is actuated and the lever associated with the bobbin includes a brake pad engaging with the bobbin for stopping same when activated.
 9. The apparatus of claim 8 wherein said means responsive to the indication means further includes: a spring means operatively coupled to said lever for accomplishing said motion, after said latch releases said lever and said means further includes a second lever engaging with said first mentioned lever for resetting same from said released condition, said latch and lever thereby holding said bobbin and pressure rollers into operative relation with said respective twirl and drive rollers.
 10. The apparatus of claim 9 wherein said detector means includes time delay means for retaining said means, for a selected interval, after said second lever is activated, said interval governed by a resistor, capacitor delay circuit and responsive to said detector means for providing a trigger signal if any one of said strands is terminated.
 11. The apparatus of claim 3 wherein said detector means further includes switch means operatively coupled with said means for producing signals indicative of reset and release conditions, for producing an enabling signal for said control means to release said latch after said lever is reset from its released position unless a terminated strand associated therewith is replaced.
 12. The apparatus as described in claim 1 wherein said detector means comprises: photodetector means responsive to each strand of yarn and each coupled to said control means for producing a signal indicative of yarn termination.
 13. The apparatus as described in claim 1, wherein said detector means comprises: means for each strand responsively coupled thereto having at least two states, a first state for providing indication of a continuous strand and a second state indicative of the termination of said strand.
 14. The apparatus as described in claim 7, further including: reset means for momentarily stopping said twirl from rotation while said bobbin is replaced thereon and said means engages with said control means for resetting said detector means.
 15. The apparatus as described in claim 7 wherein said latch includes a bar fixed at one end and engaging with the solenoid at the other end thereof having a ledge member for holding said lever in reset position and releasing same when urged laterally by the activation of said plunger, said latch beinG relatively flexible and tending to flex back to the unreleased condition when the lever is reset.
 16. The apparatus as described in claim 1 wherein said means responsive to the indication means for disengaging the bobbin out of driving relation with the bobbin drive includes: a lever, for disengaging said bobbin out of driving relation with the spindle twirl and stopping rotation thereof. 